Pulp-strainer.



G. S. WITHAM, SR.

- PULP STRAINER.

AII LIGATI ON FILED FEB. 17, 1913. 1 ,0'79,8 1 8.

Patented Nov. 25,1913.

Jim? 225 0.6 2%?" 6- G. S. WITHAM, SB-

PULP STRAINER. APPLICATION FILED FEB. 17, 1913.

Patented Nov. 25, 1913,

2 SHBETSQSHBET 2.

PLANDGRAPH C0,, WASHIN GEORGE S. WITHAM, SR., OF HUDSON FALLS, NEW YORK.

PULP-STRAINER.

Specification of Letters Patent.

Application filed February 17, 1913.

Patented Nov. 25, 1913.

Serial No. 748,972.

To all whom z't may concern:

Be it known that I, GEORGE S. VVITHAM, Sr., a citizen of the United States, residing in Hudson Falls, in the county of WVashington and State of New York, have invented certain new and useful Improvements in Pulp-Strainers, of which the following is a specification.

My invention relates to strainers of the class commonly used for screening paper pulp in which stationary screen plates are arranged horizontally in a vat and the object of my invention is to provide improved means for fastening the plates to their sup ports in the vatin such manner that they may be placed edge to edge and automatically looked as they are successively lowered to a horizontal position.

In carrying out my invention I use plates of ordinary construction and the vat may be of the usual kind. In fact my improvements may be applied to plates and vats of various forms. A vat of the usual kind may be modified to accommodate my improvements with but little change and the usual screen plates may have devices applied to them to accomplish the objects of my invention. Where screws are used to secure the lates to their supporting crossbeams much time and trouble is involved in assembling and securing the plates in position and it is desirable that the screen plates should be placed edge to edge without intervening locking mechanism and that said locking mechanism should be as simple as possible. In carrying out my invention I secure to the under side of each plate looking fingers which project laterally from the edge of the plate and which are adapted to engage locking means secured to thecross-beams and each plate is provided on its under side near its opposite edge with laterally projecting locking arms which are adapted to extend beneath the adjacent plate in the series. I always use locking fingers and locking arms or their equ1valents and in one case I attach to each crossbeam a recessed or channeled locking bar which is provided with a shoulder engaged by the locking fingers. In another case the cross-beams are recessed and have secured to them slotted locking plates with which the locking fingers engage. Or I may form recesses in the cross-beams and provide stirrup bolts with which the locking fingers interlock.

The essential characteristics of my invention are that the screen plates are placed edge to edge and are provided with looking devices which cooperate with locking means on the cross-beams in such manner that by merely placing the plates edge to edge and lowering them to a horizontal position they will automatically interlock with each other and with the cross-beams. This mechanism is used for securing the plates to all the cross-beams between the opposite ends of the vat. The first plate in the series may be provided with looking fingers engaging a recessed or channeled locking plate supported near one end of the vat, and the last plate in the series may have its outer portion supported in any suitable way and locked in place by cams or other suitable locking devices.

In the accompanying drawings, Figure 1 is a perspective view with parts broken away of a portion of a pulp screen embodying my improvements. Figs. 2 to 5 are on an enlarged scale. Fig. 2 is a detail view in cross section on the line 2-2 of Fig. 4: showing the preferred way of looking the plates to each other and to a crossbeam. Fig. 3 shows a section on the line 33 of Fig. 4. Fig. 4 is a detail plan view showing how the plates are placed edge to edge and locked to a supporting beam. Fig. 5 is a detail view with parts broken away and in longitudinal section of the strainer. Figs. 6 to 10 inclusive show a modification. Fig. 6 is a cross-sectional View showing the manner in which the plates are placed edge to edge and interlocked with each other and'with a crossbeam. Fig. '7 is a view partly in plan and partly in section on the line 77 of Fig. 6. Fig. 8 is a perspective view with parts broken away showing the manner in which the locking fingers may be formed integrally with a plate which may be secured to the under side of a screen plate. Fig. 9 is a perspective view with parts broken away of the locking plate which may be attached ther modification, Fig. 11 being a view partly in elevation and partly in section on the line 11-11 of Fig. 12, and Fig. 12 being a section on the line 1212 of Fig. 11.

The vat may be of any suitable cnstruction comprising sides A and end pieces A, A Cross-beams B for supporting the screen plates are arranged at intervals in the vat in the usual way. Each of the screen plates C is provided on its under side with locking fingers D which project laterally from its edge and each of the plates, except the last one C, is provided on its opposite edge with laterally projecting looking arms E which arms on each plate, as shown in Figs. 2 and 3, extend beneath the adjacent plate in the series.

In Figs. 1 to I have shown each of the cross-beams B as being provided with recessed or channeled bars F into which the fingers D extend, and each of these bars is provided with a shoulder f which is engaged by theends of the fingers when the plates are horizontally arranged. The outer end of. the first plate in the series has its fingers D engaged by the shoulders f of a locking bar F supported in any suitable way at the end of the vat. The outer portion of the last plate C in the series is supported on a part A of the vat. The locking bars F are attached to cross-beams in such manner that their upper faces are in the same horizontal plane and in such position as to hold the screen plates horizontally at the proper elevation. The first plate in the series is held in an inclined position so that the fingers D carried thereby extend into the recessed bar F. Then the plate is lowered to a horizontal position at which time the fingers will engage the shoulder f and the outer end of the plate is prevented from rising, while its opposite end rests on the locking bar F of the adjacent beam B. The next plate in the series is then first held in an inclined position, as indicated by dotted projecting into the recessed bar F and with the locking arms E beneath it. This second plate is then lowered until the fingers D engage the shoulder f of the locking bar and at which time the locking arms E will extend under the second plate. When in this condition the first plate is securely locked on one side to the bar F and it is locked by the arms E to. the second plate, which second plate is locked by the fingers D to the cross bar F. The other plates in the series are lowered and locked in a similar way and the outer portion of the last plate in the series may be locked to the support A by means of cams G or other suitable devices. thus be seen that the screen plates may be j very quickly lowered to their horizontal position and securely locked in place automatically as they are lowered at which time they have their edges in close contact, no locking It will means being interposed between the edges and no locking means being present in the vat above the plates except the cams G at one end of the vat. The locking devices are, for the most part, arranged on the under sides of the plates and the locking is effected by a sliding movement as the plates are lowered.

In Figs. 6 to 10 inclusive I have shown a modification in which the cross-beams B are formed with recesses Z) and a slotted plate H is secured to the beams with the slots It disposed over the recesses Z). The locking fingers D are in this instance formed integrally with a plate D which is secured by screws (1 to the underside of the screen plate C in such manner that the fingers project laterally from the edge of the plate. The plate carries on its under side locking arms E similar in all respects to those before described. The operation is substantially the same. One plate is locked to the other and to the locking means carried by the beam by first holding the finger-carryingplate in an inclined position over the beam, then lowering it to a horizontal position until the fingers engage the under side of the plate H and the fingers E project under the adjacent plate.

In the modification shown in Figs. 11 and 12. the plates are provided wit-h locking arms E and fingers D similar to those before described, while the beam B is provided with stirrup bolts I which are engaged by the fingers D in the manner clearly shown.

In every case the plates are provided with locking arms and locking fingers which engage suitable locking means carried by the cross-beams and the locking together of the plates is quickly effected by a sliding movement of the locking devices carried by the plates relatively to the locking devices carried by the beams. It is obvious that the plates may be quickly removed by first unlocking the cams and then tilting the plates and raising the successively,a very simple operation quickly performed.

I claim as my invention:

1. A pulp screen, comprising a vat having plate-supporting cross-beams, a series of screen plates each of which is provided on its under side on one edge with outwardly projecting locking fingers and on its opposite edge with outwardly projecting locking arms, and means carried by the cross-beams which engage thelocking fingers.

2. A pulp screen, comprising a vat having a series of plate-supporting cross-beams, a series of screen plates placed edge to edge, the plates in each pair having locking fingers on one plate projecting laterally beneath the other plate and locking arms on said other plate projecting laterally beneath and close to the finger-carrying plate, and

means carried by a supporting cross-beam and with locking arms extending across the which are engaged by the locking fingers and joint between the edges of adjacent plates. 10

hold both plates in a horizontal position. In testimony whereof, I have hereunto 3. A pulp screen, comprising a vat having subscribed my name. 5 plate-supporting cross-beams, recessed lock- GEORGE S. WITHAM, SR.

ing bars carried by the cross-beams, screen Witnesses: plates provided on their under sides with G. G. DURANT, Jr., locking fingers engaging said recessed bars W. H. DONALDSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

